Rice Husk Ash is rice husk that has been processed by burning. We have 2 types of rice husk ash, those are whole rice husk ask and mixed rice husk ash. - Whole rice husk Whole rice husk ash has a perfectly intact form, has maximum of 2% impurities, a maximum of 6% moisture, and less powder. Whole rice husk ash is usually used as a raw material in the manufactured of biomass. - Mixed rice ash Mixed rice husk has a more powdered form than RHA and has more than 10% impurities. This type of RHA can be used for biomass raw material also.